Display device having a suppression

ABSTRACT

An organic EL display device provided with a display portion includes a flexible base material (substrate) in which the display portion is provided, an inorganic film provided on the base material, a display element portion that is provided on the inorganic film and is provided to form the display portion, and a suppression portion that is provided outside the display portion and suppresses progression of cracking that has occurred in a peripheral portion of the base material.

TECHNICAL FIELD

The present invention relates to a display device including a displayportion, in particular, a flexible display device configured to bebendable.

BACKGROUND ART

In recent years, for example, an organic EL (electroluminescence)display device including an organic EL element and a liquid crystaldisplay device have been widely used for a television receiver, amonitor, a mobile phone, or a tablet as a flat panel display withfeatures such as a smaller thickness and a lighter weight as comparedwith the conventional cathode ray tubes.

The above-described display device is provided with a display portionthat displays information such as characters and images.

Furthermore, as the above-described display device, a flexible displaydevice configured to be bendable has been developed and put intopractical use, enabling information display to be performed by a displayportion in a bent state. That is, a display device including such adisplay portion includes a flexible substrate, and a display elementportion that is provided on the substrate and is provided to form thedisplay portion. This display device is configured to allow thesubstrate to be bent in a state in which an organic EL layer or a liquidcrystal layer, or a switching element such as a thin film transistorthat are included in the display element portion are placed on thesubstrate.

In the above-described conventional display device, a TFT layer providedwith the above-described display element portion such as a thin filmtransistor is bonded to a flexible substrate, with two layers, namely, acommonly used adhesive material layer and an adhesive material layerincluding glass fibers interposed therebetween, as described in PatentDocument 1 below, for example. Then, this conventional display device isintended to reduce the bending stress and the stress due to thermalexpansion that act on the TFT layer, thus achieving high reliability.

PRIOR ART DOCUMENT

Patent Document

[Patent Document 1] JP 2011-27822A

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

However, the above-described conventional display device may beproblematic in that adverse effects of cracking that has occurred in aperipheral portion of the substrate cannot be obviated.

Specifically, in the conventional display device, the inorganic film isgenerally provided inside the above-described TFT layer. Accordingly,stress concentration or the like may occasionally occur in the inorganicfilm inside the TFT layer during a manufacturing step or during use ofthe display device. When such stress concentration or the like occurs,cracking may occur from a peripheral portion of the substrate in theconventional display device. This cracking may expand to the inside ofthe substrate to cause defects in the display element portion, and hencethe display portion.

In view of the above-described problem, it is an object of the presentinvention to provide a highly reliable display device capable ofobviating adverse effects of cracking.

Means for Solving Problem

In order to attain the above-described object, a display deviceaccording to the present invention including a display portion, thedisplay device including;

a flexible substrate in which the display portion is provided;

an inorganic film provided on the substrate;

a display element portion that is provided on the inorganic film and isprovided to form the display portion; and

a suppression portion that is provided outside the display portion andsuppresses progression of cracking that has occurred in a peripheralportion of the substrate.

In the display device configured as above, the suppression portion isprovided outside the display portion, and suppresses the progression ofcracking that has occurred in a peripheral portion of the substrate.Consequently, unlike the conventional example, even when cracking hasoccurred in a peripheral portion of the substrate, it is possible toprevent the cracking from progressing to the inside of the displayportion. As a result, unlike the above-described conventional example,it is possible to form a highly reliable display device capable ofobviating adverse effects of cracking.

The above-described display device may include

a terminal portion that is provided on the inorganic film and connectsthe display element portion to a signal line from outside, wherein

a suppression member included in the suppression portion is providedinside the terminal portion.

In this case, the suppression member is provided inside the terminalportion. Accordingly, even when cracking has occurred in a peripheralportion of the substrate, it is possible to reliably prevent thecracking from progressing to the inside of the terminal portion, andhence the inside of the display portion.

In the above-described display device, it is preferable that thesuppression member included in the suppression portion is formed of thesame material as that of a terminal included in the terminal portion.

In this case, the suppression member and the terminal can be formed inthe same manufacturing step, making it possible to easily manufacture ahighly reliable display device capable of obviating adverse effects ofcracking.

In the above-described display device, it is preferable that asuppression member included in the suppression portion is formed of thesame material as a metal material included in the display elementportion.

In this case, the suppression member and the metal material can beformed in the same manufacturing step, making it possible to easilymanufacture a highly reliable display device capable of obviatingadverse effects of cracking.

In the above-described display device, it is preferable that asuppression member included in the suppression portion is formed of thesame material as a semiconductor material included in the displayelement portion.

In this case, the suppression member and the semiconductor material canbe formed in the same manufacturing step, making it possible to easilymanufacture a highly reliable display device capable of obviatingadverse effects of cracking.

In the above-described display device, the suppression portion mayinclude a plurality of suppression members arranged along one direction,and

end portions of the plurality of suppression members may be provided soas to overlap each other in a direction orthogonal to the one direction.

In this case, the effect of suppressing the progression of cracking bythe suppression portion can be easily enhanced, making it possible toreliably obviate adverse effects of cracking.

In the above-described display device, it is preferable that asuppression member included in the suppression portion is disposed at acenter of bending of the substrate.

In this case, the suppression member is placed at a location wherecracking tends to occur. Accordingly, the progression of cracking can bemore effectively suppressed, making it possible to more reliably obviateadverse effects of cracking.

In the above-described display device, a suppression member included inthe suppression portion may be provided with a cut-out portion at aposition corresponding to a center of bending of the substrate.

In this case, even when the substrate is bent, a damage to thesuppression member can be suppressed by the cut-out portion, making itpossible to easily inhibit the occurrence of a damage or the like to thesuppression member.

In the above-described display device, the suppression portion mayinclude a plurality of suppression members that are stacked on eachother.

In this case, the strength of the suppression member can be increased,making it possible to reliably inhibit the occurrence of a damage or thelike to the suppression member.

In the above-described display device, it is preferable that, of theplurality of suppression members, a suppression member located on abending side of the substrate has a width dimension having a valuesmaller than that of a width dimension of a suppression member locatedon a side opposite to the bending side of the substrate.

In this case, the strength of the suppression members against bending ofthe substrate can be increased, making it possible to reliably inhibitthe occurrence of a damage or the like to the suppression members.

Effects of the Invention

According to the present invention, it is possible to provide a highlyreliable display device capable of obviating adverse effects ofcracking.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view showing an organic EL display device according toEmbodiment 1 of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a pixelconfiguration of the organic EL display device.

FIG. 3 is an enlarged cross-sectional view illustrating a specificexample of a suppression member shown in FIG. 1.

FIGS. 4(a) to 4(e) are enlarged cross-sectional views each illustratinganother specific example of the suppression member shown in FIG. 1.

FIG. 5 shows diagrams illustrating a manufacturing step of the organicEL display device, with FIGS. 5(a) and 5(b) illustrating a series ofmain manufacturing steps.

FIG. 6 is a diagram illustrating a specific effect of the suppressionmember shown in FIG. 1.

FIG. 7 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 2 of the presentinvention.

FIG. 8 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to a modification of theEmbodiment 2 of the present invention.

FIG. 9 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 3 of the presentinvention.

FIGS. 10(a) and 10(b) are plan views each showing a modification of asuppression member as shown in FIG. 9.

FIG. 11 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 4 of the presentinvention.

FIG. 12 is a cross-sectional view illustrating an operation of asuppression member shown in FIG. 11.

FIG. 13 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 5 of the presentinvention.

FIGS. 14(a) and 14(b) are a plan view and a cross-sectional view,respectively, showing a configuration of a relevant portion of anorganic EL display device according to Embodiment 6 of the presentinvention.

DESCRIPTION OF THE INVENTION

Hereinafter, preferred embodiments of a display device according to thepresent invention will be described with reference to the drawings. Inthe following description, the present invention is applied to anorganic EL display device as an example. The dimensions of theconstituent members in the drawings are not faithful representation ofthe dimensions of actual constituent members, dimensional ratios ofthose members, and the like.

Embodiment 1

FIG. 1 is a plan view showing an organic EL display device according toEmbodiment 1 of the present invention. In FIG. 1, the organic EL displaydevice 1 of the present embodiment includes a base material 2 as asubstrate, and a display portion 3 that displays information such ascharacters and images. As will be described in detail later, the organicEL display device 1 of the present embodiment is provided with aninorganic film provided on the base material 2, a display elementportion that is provided on the inorganic film and is used to configurethe display portion 3, and a terminal portion 4 that is provided on theinorganic film and connects the display element portion and an externalsignal line.

The display portion 3 is provided with organic EL (electroluminescence)elements included in the above-described display element portion. Theorganic EL elements constitute a rectangular pixel area. In the pixelarea, a plurality of pixels (plurality of sub-pixels) are disposed in amatrix configuration, and the organic EL element emits light for eachsub-pixel so as to perform information display. The organic EL displaydevice 1 of the present embodiment can perform color display by formingsub-pixels of red (R), green (G), and blue (B) by the organic ELelements.

As shown in FIG. 1, a plurality of terminals 4 a provided parallel toeach other are included in the terminal portion 4. Each of the terminals4 a is configured to be connected to a signal line from outside.

Furthermore, the organic EL display device 1 of the present embodimentis provided with a suppression portion 5 that is provided outside thedisplay portion 3 and suppresses the progression of cracking that hasoccurred in a peripheral portion of the base material 2. Specifically,as shown in FIG. 1, the suppression portion 5 includes five suppressionmembers 5 a, 5 b, 5 c, 5 d, and 5 e that are provided so as to surroundthe display portion 3. That is, in the suppression portion 5, thesuppression members 5 a, 5 c, and 5 e are provided parallel to a shortside of the rectangular display portion 3, and the suppression members 5b and 5 d are provided parallel to a longer side of the rectangulardisplay portion 3. The suppression members 5 a, 5 c, and 5 e arecontinuously formed in this order.

In the suppression portion 5, the suppression members 5 a, 5 b, 5 c, 5d, and 5 e are formed of the same material and in the same manufacturingstep as a part of the above-described display element portion (thedetails of which will be described later).

In the above description, each of the suppression members 5 a to 5 e isformed by a single line in the suppression portion 5. However, thepresent embodiment is not limited thereto. Suppression members that areparallel to the corresponding suppression members 5 a to 5 e may beprovided inside and/or outside the suppression members 5 a to 5 e.Alternatively, suppression members that are stacked on the correspondingsuppression members 5 a to 5 e in the thickness direction of the basematerial 2 may be provided as in an embodiment described later.

Next, the configuration of a relevant portion of the organic EL displaydevice 1 according to the present embodiment will be described withreference to FIGS. 2 to 4.

FIG. 2 is an enlarged cross-sectional view illustrating a pixelconfiguration of the above-described organic EL display device. FIG. 3is an enlarged cross-sectional view illustrating a specific example ofthe suppression member shown in FIG. 1. FIGS. 4(a) to 4(e) are enlargedcross-sectional views each illustrating another specific example of thesuppression members shown in FIG. 1.

As shown in FIG. 2, in the organic EL display device 1 of the presentembodiment, each of the above-described pixels (sub-pixels) is providedwith a thin film transistor (TFT) 7 serving as a switching element thatcontrols the light emission of the corresponding sub-pixel.

Specifically, the inorganic film 6 is provided on the base material 2.The base material 2 is formed of a flexible (bendable) synthetic resin,for example, polyimide so as to configure the organic EL display device1 to be bendable. The inorganic film 6 is formed of, for example, aninorganic material such as silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), or silicon oxynitride (SiON). The inorganic film 6 has thefunction of a moistureproof layer, and is configured to prevent thedegradation of the thin film transistor 7 included in the displayelement portion and the organic EL element due to permeation(penetration) of moisture or oxygen from the outside.

A gate electrode 7 g of the thin film transistor 7 and a gate line (notshown) connected to the gate electrode 7 g are provided on the inorganicfilm 6. The gate electrode 7 g and the gate line (scanning line) areformed of, for example, a molybdenum film, an aluminum film, a titaniumfilm, a tungsten film, a tantalum film, a silver film, a copper film, oran alloy film thereof, or a transparent electrode material such as ITOor IZO. The gate electrode 7 g and the gate line are configured to beformed simultaneously in the same step, for example.

A gate insulating film 8 is formed so as to cover the gate electrode 7 gand the gate line. The gate insulating film 8 is formed of, for example,an inorganic material such as silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), or silicon oxynitride (SiON).

A semiconductor layer 7 h of the thin film transistor 7 is provided onthe gate insulating film 8. The semiconductor layer 7 h is formed of,for example, amorphous silicon, polysilicon, microcrystalline silicon,or an oxide semiconductor. Furthermore, as the oxide semiconductor, anIn—Ga—Zn—O-based amorphous oxide semiconductor containing In, Ga, and Znat a ratio of 1:1:1 is preferably used.

A source electrode 7 s and a drain electrode 7 d of the thin filmtransistor 7, and a source line (not shown) connected to the sourceelectrode 7 s are provided on the gate insulating film 8. The sourceelectrode 7 s, the drain electrode 7 d, and the source line (data line)are formed of, for example, a molybdenum film, an aluminum film, atitanium film, a tungsten film, a tantalum film, a silver film, a copperfilm, or an alloy film thereof or a transparent electrode material suchas ITO or IZO. The source electrode 7 s, the drain electrode 7 d, andthe source line are configured to be formed simultaneously in the samestep, for example.

A plurality of the gate lines and a plurality of the source lines areprovided, and are installed in a matrix configuration on the basematerial 2. The gate lines and the source lines are included in theabove-described display element portion, together with the thin filmtransistor 7 and the organic EL element. Then, in the organic EL displaydevice of the present embodiment, the thin film transistors 7 are placedat intersection portions of the gate lines and the source lines, and thesub-pixel area is defined by the gate lines and the source lines.Further, a gate driver and a source driver are connected (not shown) tothe gate lines and the source lines, respectively, via the terminals 4 aof the terminal portion 4. Thus, the thin film transistors 7 being inone-to-one correspondence with the sub-pixels are driven in accordancewith an image signal input from the signal lines from outside.

A protective film 9 is provided so as to cover the source electrode 7 s,the semiconductor layer 7 h, the drain electrode 7 d, and the sourceline. The protective film 9 is formed of for example, an inorganicmaterial such as silicon nitride (SiN_(x)) or silicon oxide (SiO_(x)).

A planarization layer 10 is provided on the protective film 9. Theplanarization layer 10 is formed of, for example, an organic silicon(organosilicon) such as polysiloxane or silicon carbide oxide, or anorganic material such as acrylate, polyurea, parylene, polyimide, orpolyamide.

An anode 11 and an edge cover 12 are provided on the planarization layer10. The anode 11 is formed of for example, a stack of a metal materialsuch as silver or aluminum and a transparent electrode material such asITO or IZO. The anode 11 constitutes a reflective electrode of theorganic EL element 4. Further, the anode 11 is connected to the drainelectrode 7 d of the thin film transistor 7 through contact holes formedin the protective film 9 and the planarization layer 10.

The edge cover 12 is formed on the planarization layer 10 so as to coverpattern edges of the anode 11. The edge cover 12 also functions as aninsulating layer for preventing a short circuit between the anode 11 anda cathode 14, which will be described later.

The edge cover 12 has openings, i.e., portions where the anode 11 isexposed, and these portions substantially constitute a light-emittingarea of the organic EL element 4. The organic EL display device 1 of thepresent embodiment is configured to perform full-color display byemitting, from the RGB sub-pixels, light of the corresponding color ofany of RGB. The organic EL display device 1 of the present embodimentconstitutes an active matrix type display device including thin filmtransistors 7.

As shown in FIG. 1, an organic EL layer 13 and a cathode 14 are formedon the anode 11, and the anode 11, the organic EL layer 13, and thecathode 14 constitute the above-described organic EL element. That is,the organic EL element is, for example, a light-emitting element that isdriven by a low-voltage direct current and can perform high-intensitylight emission. The organic EL element includes the anode 11, theorganic EL layer 13, and the cathode 14.

The cathode 14 is formed of, for example, a semi-transmissive electrodemade of a simple substance or an alloy of Al, Ag, Mg, Ca or the like, ora stack of a semi-transmissive electrode made of a simple substance oran alloy of Al, Ag, Mg, Ca or the like and a transparent electrodematerial such as ITO or IZO. The cathode 14 constitutes a transmissiveelectrode or a semi-transmissive electrode of the organic EL element.For example, a sealing layer (not shown) obtained by stacking aninorganic layer made of an inorganic material and an organic layer madeof an organic material is provided on the cathode 14. The sealing layeris configured to seal the organic EL element so as to prevent thedegradation of the organic EL element by preventing permeation(penetration) of moisture or oxygen from the outside.

In the organic EL layer 13, for example, a hole injection layer, a holetransport layer, a light-emitting layer, an electron transport layer, anelectron injection layer, and so forth are stacked from the anode 11side (not shown). Other than the above description, a single layer mayhave two or more functions such as a hole injection and transport layer.Further, a carrier blocking layer or the like may be inserted into theorganic EL layer 13 as appropriate.

With the configuration of the organic EL element described thus far, theorganic EL display device 1 of the present embodiment is of atop-emission type that emits light from the cathode 14 side. That is, inthe top-emission type organic EL display device 1, the surface of theanode 11 that is located on the cathode 14 side constitutes theeffective light-emitting surface of the organic EL element 4, and emitslight to the outside.

Other than the above description, a bottom-emission type organic ELdisplay device that emits light from the base material 2 side may beformed by interchanging the placement locations of the anode 11 and thecathode 14 and reversing the order of the layers in the organic EL layer13.

As illustrated in FIG. 3, a suppression member 15 is formed on theinorganic film 6 in the organic EL display device 1 of the presentembodiment. The suppression member 15 is a specific configurationexample of the suppression members 5 a to 5 e of the suppression portion5 shown in FIG. 1, and is formed, for example, of the same metalmaterial as that of the gate electrode 7 g and the gate line during themanufacturing step of the gate electrode 7 g and the gate linesimultaneously therewith.

Other than the above description, the suppression members 16, 17, 18,19, and 15 and 16 shown in FIGS. 4(a), 4(b), 4(c), 4(d), and 4(e),respectively, can be used as the suppression members 5 a to 5 e of thesuppression portion 5.

Specifically, in FIG. 4(a), the suppression member 16 is formed, forexample, of the same metal material as that of the source electrode 7 s,the drain electrode 7 d, and the source line during the manufacturingstep of the source electrode 7 s, the drain electrode 7 d, and thesource line simultaneously therewith.

In FIG. 4(b), the suppression member 17 is formed, for example, of thesame semiconductor material as that of the semiconductor layer 7 hduring manufacturing step of the semiconductor layer 7 h simultaneouslytherewith.

In FIG. 4(c), the suppression member 18 is formed, for example, of thesame metal material as that of the gate line and the source line or atransparent electrode material such as ITO or IZO during themanufacturing step of the terminal 4 a simultaneously therewith.

In FIG. 4(d), the suppression member 19 is formed, for example, of thesame metal material as that of the anode 11 during the manufacturingstep of the anode 11 simultaneously therewith.

As illustrated in FIG. 4(e), the suppression portion 5 may use thesuppression member 15 and the suppression member 16.

Other than the above description, a plurality of suppression members 15to 19 may be used as the suppression members 5 a to 5 e of thesuppression portion 5.

Next, a manufacturing method of the organic EL display device 1 of thepresent embodiment will be described with reference to FIG. 5. Note thatthe following description is focused on a step of forming the displayportion 3 and the terminal portion 4 on the base material 2, andsubsequently completing the base material 2.

FIG. 5 shows diagrams illustrating a manufacturing step of theabove-described organic EL display device, with FIGS. 5(a) and 5(b)illustrating a series of main manufacturing steps.

As shown in FIG. 5(a), for example, a release layer 21 made of a simplesubstance or a compound of tungsten, tantalum, molybdenum, titanium andthe like, or amorphous silicon, and a glass substrate 20 aresequentially attached on the lower side of the base material 2. Then, inthe organic EL display device 1 of the present embodiment, the inorganicfilm 6 is formed on the base material 2 in a state in which the basematerial 2 is stably supported by the glass substrate 20. Thereafter,the above-described display element portion including the thin filmtransistor 7 and the organic EL element, the terminal portion 4, and thesuppression portion 5 are formed on the inorganic film 6.

Subsequently, as shown in FIG. 5(b), the base material 2, the glasssubstrate 20, and the release layer 21 are separated from each other.Specifically, the interface between the base material 2 and the releaselayer 21 is separated by applying laser light from the glass substrate20 side as indicated by “H” in FIG. 5(b). This separation can beperformed smoothly by bringing the base material 2 in a slightly bentstate at the time of performing the separation. Furthermore, the organicEL display device 1 of the present embodiment is completed by performingthis separation.

Other than the above description, after separation of the base material2, a polyimide film or a film of PET, PE or the like may be attached tothe base material 2 as a support via a pressure-sensitive adhesive orthe like. Such attachment of a film is expected to achieve the effect ofpreventing the organic EL display device 1 from being easily damaged, orachieve the effect of preventing curling.

Next, effects of the suppression portion 5 will be specificallydescribed with reference to FIG. 6.

FIG. 6 is a diagram illustrating a specific effect of the suppressionmember shown in FIG. 1.

As shown in FIG. 6, when cracking CK has occurred in a peripheralportion 1out of the base material 2 as a result of bending the organicEL display device 1 during a manufacturing step or during use of theorganic EL display device 1, the cracking CK progresses toward thecentral portion 1 in side of the base material 2 (i.e., the displayportion 3 side). However, in the organic EL display device 1 of thepresent embodiment, the suppression portion 5 is provided outside thedisplay portion 3. Accordingly, as shown in FIG. 6, the progression ofthe cracking CK is suppressed by the suppression portion 5, thuspreventing the occurrence of the cracking CK inside the central portion1 in of the base material 2. The cracking CK tends to occur startingfrom an inorganic material layer, or in other words, the inorganic film6, the gate insulating film 8, and/or the protective film 9.

As a result of the verification test performed by the inventors of thepresent application, it was confirmed with an optical microscope thatthe progression of the cracking CK was successfully suppressed by thesuppression portion 5 as shown in FIG. 6. Specifically, the continuityof the stress direction in the inorganic film 6 can be broken by theprovision of the suppression portion 5. Accordingly, even when thecracking CK has occurred in the peripheral portion 1out of the basematerial 2 as a result of bending or the like of the organic EL displaydevice 1, the progression of the cracking CK can be suppressed by thesuppression portion 5.

In the organic EL display device 1 of the present embodiment configuredin the above-described manner, the suppression portion 5 is providedoutside the display portion 3, and suppresses the progression ofcracking that has occurred in the peripheral portion of the basematerial 2. Consequently, unlike the conventional example, even whencracking has occurred in a peripheral portion of the base material 2, itis possible, with the organic EL display device 1 of the presentembodiment, to suppress the cracking from progressing to the inside ofthe display portion 3. As a result, unlike the conventional example, thepresent embodiment makes it possible to form a highly reliable organicEL display device 1 capable of obviating adverse effects of cracking,such as the occurrence of defects or the like in the display elementportion, and hence the display portion 3.

In the present embodiment, the suppression members 15, 16, 18, and 19included in the suppression portion 5 are formed of the same material asthe metal material included in the display element portion. Accordingly,the suppression members 15, 16, 18, and 19 and the metal material can beformed in the same manufacturing step, making it possible to easilymanufacture a highly reliable organic EL display device 1 capable ofobviating adverse effects of cracking.

In the present embodiment, the suppression member 17 included in thesuppression portion 5 is formed of the same material as thesemiconductor material included in the display element portion.Accordingly, the suppression member 17 and the semiconductor materialcan be formed in the same manufacturing step, making it possible toeasily manufacture a highly reliable organic EL display device 1 capableof obviating adverse effects of cracking.

Embodiment 2

FIG. 7 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 2 of the presentinvention.

In FIG. 7, the present embodiment differs from Embodiment 1 above mainlyin that the suppression members included in the suppression portion areprovided inside the terminal portion. Note that the same components asthose of Embodiment 1 are denoted by the same reference numerals, andthe redundant description thereof has been omitted.

That is, as shown in FIG. 7, in the organic EL display device 1 of thepresent embodiment, the suppression members 5 f included in thesuppression portion 5 are provided inside the terminal portion 4.Specifically, the terminals 4 a and the suppression members 5 f areprovided inside the terminal portion 4 such that the terminals 4 a andthe suppression members 5 f are alternately disposed.

The suppression members 5 f are formed, for example, of the same metalmaterial as that of the gate lines and the source lines of the terminals4 a or a transparent electrode material such as ITO or IZO in themanufacturing step of the terminals 4 a simultaneously therewith.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 1 above.

In the present embodiment, the suppression members 5 f are providedinside the terminal portion 4. Accordingly, even when cracking hasoccurred in a peripheral portion of the base material 2, it is possibleto reliably prevent the cracking from progressing to the inside of theterminal portion 4, and hence the inside of the display portion 3.

In the present embodiment, the suppression members 5 f included in thesuppression portion 5 are formed of the same material as that of theterminals 4 a included in the terminal portion 4. Accordingly, thesuppression members 5 f and the terminals 4 a can be formed in themanufacturing step, making it possible to easily manufacture a highlyreliable organic EL display device 1 capable of obviating adverseeffects of cracking.

Other than the above description, the suppression members 5 f may beformed by using a material different from that of the terminals 4 a, forexample, the same semiconductor material as that of the semiconductorlayer 7 h.

Modification of Embodiment 2

FIG. 8 is a plan view of a configuration of a relevant portion of amodification of the organic EL display device according to Embodiment 2of the present invention.

In FIG. 8, the present modification differs from Embodiment 2 abovemainly in that, in the suppression portion, a plurality of suppressionmembers are provided between two adjacent terminals so as to be parallelto the terminals.

That is, as shown in FIG. 8, in the organic EL display device 1 of thepresent modification, a plurality of, for example, three suppressionmembers 5 f 1, 5, and 5 f 3 included in the suppression portion 5 areprovided inside the terminal portion 4. Specifically, inside theterminal portion 4, the suppression members 5 f 1, 5 f 2, and 5 f 3 aresequentially disposed between two adjacent terminals 4 a so as to beparallel to the terminals 4 a.

The suppression members 5 f 1, 5 f 2, and 5 f 3 are formed, for example,of the same metal material as that of the same gate line and sourcelines of the terminals 4 a or a transparent electrode material such asITO or IZO during the manufacturing step of the terminals 4 asimultaneously therewith.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 2 above.

Other than the above description, the suppression members 5 f 1, 5 f 2,and 5 f 3 may be formed by using a material different from that of theterminals 4 a, for example, the same semiconductor material as that ofthe semiconductor layer 7 h.

Embodiment 3

FIG. 9 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 3 of the presentinvention.

In FIG. 9, the present embodiment differs from Embodiment 1 above mainlyin that, in the suppression portion, a plurality of suppression membersare provided such that they are arranged along one direction and endportions thereof overlap each other in a direction orthogonal to the onedirection. Note that the same components as those of Embodiment 1 aredenoted by the same reference numerals, and the redundant descriptionthereof has been omitted.

That is, as shown in FIG. 9, in the organic EL display device 1 of thepresent embodiment, a plurality of for example, three suppressionmembers 25 a and a plurality of for example, two suppression members 25b are provided in a suppression portion 25. The suppression members 25 aand 25 b are configured linearly. Further, the suppression members 25 aand 25 b are disposed such that they are arranged alternately in anup-down direction in (one direction) in FIG. 9, and end portions thereofoverlap each other in a direction orthogonal to the up-down direction.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 1 above.

In the present embodiment, a plurality of suppression members 25 a and25 b arranged in one direction are included in the suppression portion25, and end portions of the plurality of suppression members 25 a and 25b are provided so as to overlap each other in a direction orthogonal tothe one direction. Consequently, in the present embodiment, the effectof suppressing the progression of cracking by the suppression portion 25can be easily enhanced, making it possible to reliably obviate adverseeffects of cracking.

Further, each of the suppression members 25 a and 25 b of the presentembodiment is formed to be shorter than the suppression member ofEmbodiment 1. Accordingly, it is possible to prevent formation of anunnecessary parasitic capacitance in the organic EL display device 1.

Modifications of Embodiment 3

FIGS. 10(a) and 10(b) are plan views each showing a modification of thesuppression members shown in FIG. 9.

In FIGS. 10(a) and 10(b), the present modifications differ fromEmbodiment 3 above mainly in that the shape of each of the plurality ofsuppression members of the suppression portion is changed.

That is, as shown in FIG. 10(a), in the organic EL display device 1 ofthe present modification, a plurality of for example, five suppressionmembers 35 a are provided in a suppression portion 35. The suppressionmembers 35 a are configured linearly. Further, the suppression members35 a are disposed such that they are arranged at a predetermined anglealong an up-down direction (one direction) in FIG. 10(a), and endportions thereof overlap each other in a direction orthogonal to theup-down direction.

As shown in FIG. 10 (b), in an organic EL display device 1 of anothermodification, a plurality of, for example, three suppression members 45a and a plurality of for example, two suppression members 45 b areprovided in a suppression portion 45. The suppression members 45 a and45 b are configured in a shape having a bent portion. Further, thesuppression members 45 a and 45 b are disposed such that they arearranged alternately in an up-down direction (one direction) in FIG. 10(b), and end portions thereof overlap each other in a directionorthogonal to the up-down direction.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 3 above.

Embodiment 4

FIG. 11 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 4 of the presentinvention. FIG. 12 is a cross-sectional view illustrating an operationof a suppression member shown in FIG. 11.

In FIGS. 11 and 12, the present embodiment differs from Embodiment 1above mainly in that, in the suppression portion, the suppressionmembers are provided at a center of bending of the base material. Notethat the same components as those of Embodiment 1 above are denoted bythe same reference numerals, and the redundant description thereof hasbeen omitted.

That is, as shown in FIG. 11, in the organic EL display device 1 of thepresent embodiment, suppression members 55 a are disposed at a center ofbending C of the base material 2 (i.e., a center of bending of theorganic EL display device 1) in a suppression portion 55. Further,except for the vicinity of the center of bending C, the base material 2is formed of a material having a relatively high rigidity.

As described above, the suppression members 55 a are disposed at thecenter of bending C of the base material 2. Accordingly, the suppressionmembers 55 a are disposed at a location where cracking tends to occurwhen the organic EL display device 1 is bent as indicated by “K” in FIG.12.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 1 above.

In the present embodiment, the suppression members 55 a included in thesuppression portion 55 are disposed at the center of bending C of thebase material 2. Consequently, in the present embodiment, thesuppression members 55 a are placed at a location where cracking tendsto occur. Accordingly, the progression of cracking can be moreeffectively suppressed, making it possible to more reliably obviateadverse effects of cracking.

Further, the suppression members 55 a of the present embodiment areconfigured to be shorter than the suppression member of Embodiment 1.Accordingly, it is possible to prevent formation of an unnecessaryparasitic capacitance in the organic EL display device 1.

Embodiment 5

FIG. 13 is a plan view showing a configuration of a relevant portion ofan organic EL display device according to Embodiment 5 of the presentinvention.

In FIG. 13, the present embodiment differs from Embodiment 1 abovemainly in that cut-out portions are provided in the suppression memberat positions corresponding to a center of bending of the base material.Note that the same components as those of Embodiment 1 above are denotedby the same reference numerals, and the redundant description thereofhas been omitted.

That is, as shown in FIG. 13, in the organic EL display device 1 of thepresent embodiment, cut-out portions 65 b and 65 c are provided in asuppression member 65 a of a suppression portion 65 at positionscorresponding to a center of bending C1 of the base material 2.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 1 above.

In the present embodiment, the cut-out portions 65 b and 65 c areprovided in the suppression member 65 a at positions corresponding tothe center of bending C1 of the base material 2. Accordingly, even whenthe base material 2 is bent, a damage to the suppression member 65 a canbe suppressed by the cut-out portions, making it possible to easilyinhibit the occurrence of a damage or the like to the suppression member65 a.

Embodiment 6

FIGS. 14(a) and 14(b) are a plan view and a cross-sectional view,respectively, showing a configuration of a relevant portion of anorganic EL display device according to Embodiment 6 of the presentinvention.

In FIG. 14, the present embodiment differs from Embodiment 1 abovemainly in that two suppression members that are stacked on each otherare used in the suppression portion. Note that the same components asthose of Embodiment 1 above are denoted by the same reference numerals,and the redundant description thereof has been omitted.

That is, as shown in FIGS. 14(a) and 14(b), in the organic EL displaydevice 1 of the present embodiment, a plurality of, for example, twosuppression members 75 a and 75 b are stacked on each other in asuppression portion 75. Further, in the suppression members 75 a and 75b, width dimensions respectively indicated by “H1” and “H2” in FIG.14(b) are set to be a value in the range from 2 to 50 μm and a value inthe range from 2 to 50 μm, for example.

Further, in the suppression portion 75, the suppression member 75 a isdisposed on the bending side of the base material 2, and the suppressionmember 75 b is disposed on a side opposite to the bending side of thebase material 2.

Specifically, in the suppression portion 75, the suppression member 75 bis formed by using the same metal material as that of the source lines,and the suppression member 75 a is formed by using the samesemiconductor material as that of the semiconductor layer 7 h.

Other than the above description, the suppression member 75 b may beformed by using the same metal material as the gate lines, and thesuppression member 75 a may be formed by using the same metal materialas the source lines. Also, the gate insulating film 8 and thesemiconductor layer 7 h between the suppression members 75 b and thesuppression member 75 a may be formed so as to be open.

With the configuration described thus far, the present embodiment canachieve the same operation and effects as those of Embodiment 1 above.

In the present embodiment, the two suppression members 75 a and 75 bthat are stacked on each other are used in the suppression portion 75.Accordingly, the strength of the suppression members 75 a and 75 b canbe increased, making it possible to reliably inhibit the occurrence of adamage or the like to the suppression members 75 a and 75 b.

In the present embodiment, of the plurality of suppression members 75 aand 75 b, the suppression member 75 a located on the bending side of thebase material 2 preferably has a width dimension having a value smallerthan that of the suppression member 75 b located on a side opposite tothe bending side of the base material 2. With this configuration, thestrength of the suppression members 75 a and 75 b against bending of thebase material 2 can be increased in the present embodiment, making itpossible to reliably inhibit the occurrence of a damage or the like tothe suppression members 75 a and 75 b.

The above embodiments are shown merely for an illustrative purpose andare not limiting. The technical scope of the present invention isdefined by the appended claims, and all changes that come within therange of equivalency of the claims are intended to be embraced therein.

For example, in the foregoing description, the present invention isapplied to the organic EL display device. However, the present inventionis not limited in any way as long as the display device includes aflexible substrate in which a display portion is provided, an inorganicfilm provided on the substrate, a display element portion that isprovided on the inorganic film and is provided to form the displayportion, and a suppression portion that is provided outside the displayportion and suppresses progression of cracking that has occurred in aperipheral portion of the substrate. Specifically, the present inventionis applicable to an inorganic EL display device that uses an inorganicEL element including an inorganic compound, for example. The presentinvention is also applicable to a liquid crystal display deviceincluding a liquid crystal layer.

In the above description, the present invention is applied to an activematrix type organic EL display device including thin film transistors(TFTs) 7. However, the present invention is not limited thereto, and isalso applicable to a passive matrix type organic EL display deviceincluding no thin film transistor.

Other than the above description, the present invention is alsoapplicable to an organic EL display device including an opposingsubstrate that is formed of a flexible material and is provided so as tooppose the base material 2.

In the above description, the suppression member of the suppressionportion is provided on the upper side (the side opposite to the basematerial) of the inorganic film. However, the present invention is notlimited thereto, and the suppression member of the suppression portionmay be provided on the lower side (i.e., between the inorganic film andthe base material) of the inorganic film.

Other than the above description, Embodiments 1 to 6 above may becombined as appropriate.

INDUSTRIAL APPLICABILITY

The present invention is useful for a highly reliable display devicecapable of obviating adverse effects of cracking.

LIST OF REFERENCE NUMERALS

-   -   1 Organic EL display device (display device)    -   2 Base material (substrate)    -   3 Display portion    -   4 Terminal portion    -   4 a Terminal    -   5, 25, 35, 45, 55, 65, 75 Suppression portion    -   5 a, 5 b, 5 c, 5 d, 5 e, 5 f, 5 f 1, 5 f 2, 5 f 3, 15, 16, 17,        18, 19, 25 a, 35 a, 45 a, 55 a, 65 a,    -   75 a, 75 b Suppression member    -   7 Thin film transistor (display element portion)    -   7 s Source electrode (display element portion)    -   7 g Gate electrode (display element portion)    -   7 d Drain electrode (display element portion)    -   7 h Semiconductor layer (display element portion)    -   11 Anode (display element portion)    -   13 Organic EL layer (display element portion)    -   14 Cathode (display element portion)

The invention claimed is:
 1. A display device including a displayportion, the display device comprising: a flexible substrate in whichthe display portion is provided; an inorganic film with a plurality oflayers provided on the substrate; a display element portion that isprovided on the inorganic film and is provided to form the displayportion; and a suppression portion that is provided outside the displayportion and suppresses progression of cracking that has occurred in aperipheral portion of the substrate, wherein the plurality of layers ofthe inorganic film includes a first inorganic film and a secondinorganic film formed on the first inorganic film, and the suppressionportion k defined by a metal material between the first inorganic filmand the second inorganic film.
 2. The display device according to claim1, comprising a terminal portion that is provided on the inorganic filmand connects the display element portion to a signal line from outside,wherein a suppression member included in the suppression portion isprovided inside the terminal portion.
 3. The display device according toclaim 2, wherein the suppression member included in the suppressionportion is formed of the same material as that of a terminal included inthe terminal portion.
 4. The display device according to claim 1,wherein a suppression member included in the suppression portion isformed of the same material as a metal material included in the displayelement portion.
 5. The display device according to claim 4, wherein thesuppression member is formed of the same material as a gate line and agate electrode.
 6. The display device according to claim 4, wherein thesuppression member is formed of the same material as a source electrode,a drain electrode and a source line.
 7. The display device according toclaim 1, wherein the suppression portion includes a plurality ofsuppression members arranged along one direction, and end portions ofthe plurality of suppression members are provided so as to overlap eachother in a direction orthogonal to the one direction.
 8. The displaydevice according to claim 1, wherein a suppression member included inthe suppression portion is disposed to intersect a bending portion ofthe substrate.
 9. The display device according to claim 1, wherein asuppression member included in the suppression portion is provided witha cut-out portion at a position corresponding to a bending portion ofthe substrate.
 10. The display device according to claim 1, wherein thesuppression portion includes a plurality of suppression members that arestacked on each other.
 11. The display device according to claim 10,wherein, of the plurality of suppression members, a suppression memberlocated on a bending side of the substrate has a width dimension havinga value smaller than that of a width dimension of a suppression memberlocated on a side opposite to the bending side of the substrate.
 12. Thedisplay device according to claim 10, wherein of the plurality ofsuppression members, a first suppression member includes a metalmaterial provided between the first inorganic film and the secondinorganic film, and a second suppression member includes a metal layerprovided on an upper layer of the second inorganic film, and an openingis defined in the second inorganic film in a formation region of thesuppression members so that the first suppression member and the secondsuppression member are in contact with each other.
 13. The displaydevice according to claim 1, wherein the suppression portion surroundsthe display portion and is continuously defined except for a terminalportion that connects the display element portion to a signal line fromoutside.
 14. The display device according to claim 1, wherein thesuppression portion is provided so as to surround a display portion.